Commodore 64C - Interpreting Screen Messages

screen messages
If you press the RETURN without having entered something that the computer can
understand, you may see a message on the screen from the computer (e.g., SYN
TAX ERROR). These messages arc the computer's way of telling you that it can't
act on the information you have entered. In some cases the messages arc self-
explanatory, but in some cases you may need an explanation of the message.
Appendix A of the Commodore 64C System Guide lists and explains the error
messages for the 64C.